Techniques of Controlling Salinity in Irrigated Agriculture for Sustainability

Worldwide 10-50 per cent of irrigated agriculture is facing problems of waterlogging and soil salinity which cause loss of around 1.5 million hectare land annually. The problems of alkalinity and salinity coupled with waterlogging affect about 7.3 million hectares land in India, which reduce agricultural productivity. At the same time agriculture is facing increase in water demand at 2.4 per cent annually during 2005 -2030 as well as reducing share of water due to competing demand from industry and urbanizations. Therefore, to fulfill food and nutritional security of nation on sustained basis, both salt affected soils and waters need to be managed using appropriate techniques. Techniques for controlling salinity that require relatively minor changes are more frequent irrigations, selection of more salt-tolerant crops, additional leaching, residue management, chemical amendments, pre-plant irrigation, bed forming and seed placement. These require significant changes in management such as, changing the irrigation method, altering the water supply, land-leveling, modifying the soil profile, and installing surface as well as subsurface drainage. Where possible, furrow planting may help in obtaining better stands and crop yields under saline conditions. Studies have shown that yield obtained by the drip method with saline water was almost equal to that produced when the high quality water was applied by this method. Therefore, improved agricultural production and water productivity on sustained basis could be realized by application of techniques to manage salt affected soils and waters.